You can extend the life of mussels by storing them properly overnight. The shellfish need to stay alive until you cook them, or they will spoil. Mussels need to remain moist, but they do not need to be immersed in water for a long amount of time. They also need enough air to breathe so that they do not suffocate. After you prepare the mussels, they can be stored in an airtight container in the refrigerator or freezer.
Place the mussels in a bowl large enough to hold them.
Dampen a hand towel with water. Cover the bowel with the damp towel.
Place the bowl in the refrigerator. Do not allow them to freeze. Drain off the water when it accumulates in the bowl.
Tap on the mussel shells before you prepare them. If the shells do not close, discard the mussels because they are dead.
Use live mussels within two to three days after you purchase them. Do not store live mussels in water.